SI-14_non-persistence

SI-14 Non-persistence

High-Level Description

Family: System and Information Integrity (SI) Framework: NIST SP 800-53 Rev 5

Implementation of non-persistent components and services mitigates risk from advanced persistent threats (APTs) by reducing the targeting capability of adversaries (i.e., window of opportunity and available attack surface) to initiate and complete attacks. By implementing the concept of non-persistence for selected system components, organizations can provide a trusted, known state computing resource for a specific time period that does not give adversaries sufficient time to exploit vulnerabilities in organizational systems or operating environments. Since the APT is a high-end, sophisticated threat with regard to capability, intent, and targeting, organizations assume that over an extended period, a percentage of attacks will be successful. Non-persistent system components and services are activated as required using protected information and terminated periodically or at the end of sessions. Non-persistence increases the work factor of adversaries attempting to compromise or breach organizational systems.

Non-persistence can be achieved by refreshing system components, periodically reimaging components, or using a variety of common virtualization techniques. Non-persistent services can be implemented by using virtualization techniques as part of virtual machines or as new instances of processes on physical machines (either persistent or non-persistent). The benefit of periodic refreshes of system components and services is that it does not require organizations to first determine whether compromises of components or services have occurred (something that may often be difficult to determine). The refresh of selected system components and services occurs with sufficient frequency to prevent the spread or intended impact of attacks, but not with such frequency that it makes the system unstable. Refreshes of critical components and services may be done periodically to hinder the ability of adversaries to exploit optimum windows of vulnerabilities.

What to Check

• Verify SI-14 Non-persistence is documented in SSP
• Confirm control is operating effectively
• Review evidence of continuous monitoring for SI-14

How to Test

Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SI-14 implementation details. Verify the organization has documented how this control is satisfied.

Step 2: Validate Implementation

# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null

Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

Tools

Remediation Guide

Control Statement

Implement non-persistent [organization-defined] that are initiated in a known state and terminated [organization-defined].

Implementation Guidance

Implementation of non-persistent components and services mitigates risk from advanced persistent threats (APTs) by reducing the targeting capability of adversaries (i.e., window of opportunity and available attack surface) to initiate and complete attacks. By implementing the concept of non-persistence for selected system components, organizations can provide a trusted, known state computing resource for a specific time period that does not give adversaries sufficient time to exploit vulnerabilities in organizational systems or operating environments. Since the APT is a high-end, sophisticated threat with regard to capability, intent, and targeting, organizations assume that over an extended period, a percentage of attacks will be successful. Non-persistent system components and services are activated as required using protected information and terminated periodically or at the end of sessions. Non-persistence increases the work factor of adversaries attempting to compromise or breach organizational systems.

Non-persistence can be achieved by refreshing system components, periodically reimaging components, or using a variety of common virtualization techniques. Non-persistent services can be implemented by using virtualization techniques as part of virtual machines or as new instances of processes on physical machines (either persistent or non-persistent). The benefit of periodic refreshes of system components and services is that it does not require organizations to first determine whether compromises of components or services have occurred (something that may often be difficult to determine). The refresh of selected system components and services occurs with sufficient frequency to prevent the spread or intended impact of attacks, but not with such frequency that it makes the system unstable. Refreshes of critical components and services may be done periodically to hinder the ability of adversaries to exploit optimum windows of vulnerabilities.

Risk Assessment

CWE Categories

References

• NIST SP 800-53 Rev 5 - SI-14
• NIST SP 800-53A Rev 5 (Assessment Procedures)
• NIST SP 800-53 Rev 5 Full Catalog

Checklist

• Control documented in SSP
• Implementation evidence collected
• Operating effectiveness validated
• Continuous monitoring in place
• Related controls (SC-30, SC-34, SI-21) reviewed